Most eastern tent caterpillar (ETC)
egg masses should have hatched by now in central Kentucky. Scattered observations
point to an overall population level comparable to 2003. Caterpillar numbers
should be well below area-wide outbreak levels but there will be some strong
local pockets of infestation. Careful inspection of wild cherry and related
trees is the way to assess the situation on your farm. Now is the time to begin
looking.

ETC larvae are still very small but
they are feeding on leaf buds and have started to form tents at branch angles.
The tents will become more visible as the caterpillars grow and add to the structure.
This will be the key to use and determine treatment sites and timing. At this
point, the first full week of April should be the time to assess treatment with
continued inspections as needed.

Caterpillar management options are
the same as those recommended for 2003. Foliar sprays of Bacillus thuringiensis
(Bt) products or the pyrethroid Talstar should be made when the tents are
about the size of a baseball.

Bt residues must be eaten by the
caterpillars so treatment should be directed at foliage around active tents.
Bt products are most effective against caterpillars that are no more than 1
inch long. Residues of these products are broken down by sunlight and remain
on the foliage for less than one week. Two applications of Bt products may be
needed for adequate control. Mortality results from disruption of the gut lining
of the caterpillars so they do not die until several days after ingesting the
material.

The pyrethroid Talstar has contact
and stomach poison activity and has a residual life of about 1 week after application.
As with Bt products, targeted applications should be used, not full tree sprays.

Trunk injections of Bidrin have been
used successfully to control ETC larvae. As with foliar sprays, baseball-sized
tents are a good clue for timing treatment if injection is warranted.